下列树种中，适合于厂矿绿化、抗污染能力最强的树种是（）
A.梅花
B.构树
C.广玉兰
D.杨梅
参考答案：B
—I'm sorry that I failed my English test.
—_____ Do better next time.[ ]
A. How about sleeping?
B. Why not tell me?
C. It doesn't matter.
D. Help yourself.
光线垂直于地面，我们称这种投影方法为正投影法。
